Auth bypass in Thalesgroup Sentinel Keys Server
CVE-2026-78403
Stack-based buffer overflow and missing authorization vulnerability in Thales Sentinel Keys Server on Windows allows Overflow Buffers. Sentinel Keys Server does not check the length of the first field in the HTTP request. An attacker may craft an HTTP request and send it to Sentinel Keys Server. It may lead to remote code execution as NT AUTHORITY\SYSTEM. This issue affects Sentinel Keys Server: versions lower than 1.3.8.0.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- supportportal.thalesgroup.com/csm (vendor-advisory)
Frequently asked questions
- What is CVE-2026-78403?
- CVE-2026-78403 is a critical-severity vulnerability in Thalesgroup Sentinel Keys Server, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-10-30.
- How severe is CVE-2026-78403?
- Critical severity. CVSS v3 base score is 9.8 out of 10.